The invention relates to a base for a cartridge lamp of the type having at least one filament mounted on filament support legs extending through a seal of the bulb for external mounting on electrically-conducting terminals.
Typically, conventional lamps have consisted of at least one filament enclosed in a bulb which bulb is then glued or otherwise affixed in a known manner to an electrically conducting lamp base to form an integral unit for installation in a conventional socket. When sealed to the bulb, the lamp base was found, in many cases, to be inaccurately aligned with respect to the filament so that in critical applications when the base is inserted into the socket, as for instance, by screwing a threaded base into a threaded socket, the filament within the bulb was not properly positioned.
An attempt to overcome this misalignment problem is disclosed in the invention of a baseless cartridge lamp U.S. Pat. No. 4,061,940, incorporated herein by reference. The cartridge lamp comprises at least one filament mounted on filament support legs carried through and sealed into the bulb. The support legs provide means for external electrical connection and mechanical mounting on supporting terminals.
Also disclosed in that patent is a socket for holding a lamp of this design. The socket disclosed therein, however, holds the lamp filament generally parallel to the longitudinal axis of the base of the socket which is not a very practical arrangement for use with a reflector. The prior art lamps utilizing an integral base are also limited in that the base requires a great deal of space external to the reflector assembly.
In many cases, when these reflector assemblies are installed on motor vehicles and the like, there exists much less room for the removal and replacement of these lamps than would be desirable for maintain-ability standards. Additionally, in a great number of cases, the only way that a lamp can be replaced is through the removal of the entire lamp-reflector assembly.